5916 research outputs found
Sort by
Publisher Correction: Observation of triple J/ψ meson production in proton-proton collisions
No full textCorrection to: Nature Physics, published online 19 January 2023. In the version of the article initially published, the second affiliation of T. Elkafrawy was incorrect and is now shown as Ain Shams University, Cairo, Egypt in the HTML and PDF versions of the article.Publisher versio
Distance education at tourism higher education programs in developing countries: Case of Türkiye with a strategic perspective and recommendations
No full textThe COVID-19 pandemic was a critical and sudden happening for higher education institutions to adapt fast to changes and switch to distance education (DE). In addition to presenting several challenges and threats such as insufficient internet infrastructure and limited technology tools in developing countries, this sudden transition brought about some opportunities as well. This research focuses on the DE experiences of instructors in tourism-related higher education programs (THEP) and aims to propose a strategic view and recommendations based on instructors’ evaluations. Qualitative research methods are applied, and data is collected from 114 instructors via Google Forms. The originality of the research is based on the strategic view proposed by the application of SWOT and TOWS analyses. The proposed strategies are expected to help the preparation of effective educational, tactical, and operational plans by the regulatory authorities
Metaheuristic approaches for maximum blood collection problem
No full textThanks to recent technological and medical advances, blood components can now be extracted from whole blood after a donation. One of such components is the platelet, which has a wide range of uses in medical fields, including cancer treatment and other surgical procedures. Due to the perishable nature of platelets, it is recommended that the separation occurs within six hours after the donation. Moreover, platelets constitute less than one percent of the whole blood volume, yet they are highly demanded. Thus, it becomes apparent that there is a need for an effective platelet supply chain that meets patient needs. Given the importance of platelets in healthcare, their perishability, and their limited supply, an effective platelet supply chain leans on well-managed whole blood collection operations. In this study, we consider a blood collection problem (BCP) focusing on the collection of whole blood donations from the blood donation sites (BDS). Different from the basic form of BCP, we consider processing time limit of blood and arbitrary donation patterns of donors as well as relaxing the assumption of assigning each blood collection vehicle (BCV) to a set of BDSs. Therefore, we define the non-clustered maximum blood collection problem (NC-MBCP) as a variant of BCP. In this problem, the goal is to maximize the total platelets collected from numerous BDSs utilizing a set of BCVs that collect blood from those BDSs and transfer it to a central processing facility before it becomes non-usable for platelet production. In this study, we examine routing decisions for platelet collections while relaxing the clustering requirement from the BDSs, resulting in a significant increase in the complexity of the problem. In order to solve the problem, we propose a hybrid genetic algorithm and an invasive weed optimization algorithm that provide considerable improvements over the best solution in the literature for the clustered variant of the problem and outperform it by 9.40% improvement by the hybrid genetic algorithm and 9.14% improvement by the invasive weed optimization algorithm on average.Son teknolojik ve tıbbi gelişmeler sayesinde, kan bileşenleri artık bir bağıştan sonra tam kandan elde edilebilmektedir. Bu bileşenlerden biri de, kanser tedavisi ve diğer cerrahi işlemler de dahil olmak üzere tıp alanlarında geniş bir kullanım alanına sahip olan trombosittir. Trombositlerin çabuk bozulan yapısı nedeniyle, bağıştan sonra altı saat içinde ayrılması önerilmektedir. Ayrıca, trombositler tam kan hacminin yüzde birinden daha azını oluşturmasına rağmen oldukça talep görmektedir. Böylece, hasta ihtiyaçlarını karşılayan etkin bir trombosit tedarik zincirine ihtiyaç olduğu ortaya çıkmaktadır. Trombositlerin sağlık hizmetlerindeki önemi, çabuk bozulabilirlikleri, sınırlı tedarikleri ve etkili trombosit tedarik zinciri, iyi yönetilen tam kan alma işlemlerine dayanmaktadır. Bu çalışmada, kan bağışı merkezlerinden (BDS) tam kan bağışlarının toplanmasına odaklanılan bir kan alma problemi (BCP) ele alınmaktadır. BCP'nin temel halinden farklı olarak, her bir kan toplama aracını (BCV) bir dizi BDS'lere atama varsayımını esnetmenin yanı sıra, kanın işlem süresi sınırını ve donörlerin keyfi bağış modellerini ele almaktayız. Bu nedenle, kümelenmemiş maksimum kan alma problemini (NC-MBCP) BCP'nin bir çeşidi olarak tanımlanmaktadır.Bu problemdeki amaç, BDS'lerden kan toplayan ve trombosit üretimi için kullanılamaz hale gelmeden önce bir merkezi işleme tesisine aktaran bir dizi BCV'yi kullanarak çok sayıda BDS'den toplanan toplam trombositleri maksimize etmektir. Bu çalışmada, problemin karmaşıklığında önemli bir artışla sonuçlanan BDS'lerden kümeleme gereksinimini esnetirken trombosit toplamaları için rotalama kararları incelenmektedir. Problemi çözmek için, problemin kümelenmiş varyantı için literatürdeki en iyi çözüm üzerinde önemli iyileştirmeler sağlayan bir hibrit genetik algoritma ve bir istilacı yabani ot optimizasyon algoritması önerilmektedir. Önerilen hibrit genetik algoritma ortalama %9,40 ve istilacı yabani ot optimizasyon algoritması ile ortalama %9,14 iyileştirme ile daha iyi performans göstermektedirler
Effect of friction stir processing on the fatigue performance of AZ31 magnesium alloy
No full textHerein, the cyclic mechanical behavior of AZ31 magnesium alloy after multipass friction stir processing (FSP) is investigated up to the very high-cycle fatigue (VHCF) regime. The grain refinement and texture evolution after processing are evaluated to enhance the understanding of the fatigue response. Although ultimate tensile strength and ductility of the friction stir processed AZ31 increase up to about 320 MPa and 25%, respectively, the fatigue performance deteriorates in comparison with that of the as-received condition due to the low yield strength and texture evolution after processing. Furthermore, analysis of fracture surfaces of the samples after cyclic loading reveals that the as-received AZ31 is more prone to brittle fracture with multiple-origin fatigue failure even at low stress amplitudes. On the contrary, the dominant failure mechanisms of the friction stir processed samples are initiation and propagation of cracks originating from the surface, porosities, and grain size inhomogeneity. Nevertheless, the capability of FSP for providing superior crack initiation resistance in the VHCF regime is demonstrated as a significant contribution. Based on a detailed study of prevalent microstructural features, processing–property–damage relationships are established indicating the major effect of FSP on the final performance of the AZ31 magnesium alloy.BAGEP Award of the Science Academy, Turkey ; Hessen State Ministry for Higher Education, Research and the Arts, German
Exploring the multifractality in the precious metal market
No full textThis study proposes a novel approach to investigating the multifractality of time series using the multifractal cross-correlation detrended moving average analysis (MF-X-DMA). The study demonstrates the behavioral differences of MF-X-DMA in coherent and non-coherent time periods. Due to the lack of a mechanism to capture the dynamical cross-correlation in time series, correlated time series with multifractal structure present a barrier for analysis. The study shows that when the wavelet coherence method is applied to time series, co-movement between time series can be easily captured in certain time intervals, providing an efficient way to find time intervals to apply MF-X-DMA. The study applies the wavelet coherence method to the daily spot prices of gold and platinum from January 1987. It shows that the wavelet coherence method is an excellent engine to extract designated time series in certain frequency and time intervals, eliminating the need for windowing or shuffling methods. Additionally, the study observes a long-term power law cross-correlation using detrended cross-correlation analysis coefficients of inversed series for both low-correlated and high-correlated series. Finally, the findings indicate that MF-X-DMA leads to superior results compared to MF-DFA when provided with highly correlated data
Transdisciplinarity as a learning challenge: Student experiences and outcomes in an innovative course on wearable and collaborative robotics
No full textContribution: This study provides evidence for the benefit of short online courses for transdisciplinary competence development of graduate students. It shows the significant challenges students face while learning, and provides instructional recommendations to improve students’ learning quality and professionalism. Background: Developing wearable and collaborative robots
requires industry collaboration and transdisciplinary competence. Industry’s involvement in long-term programs is becoming infeasible, and the nature of transdisciplinary learning has not been explored to inform instructional practices. Intended Outcomes: This study aimed to provide instructional
recommendations based on an in-depth examination of a diverse group of graduate students’ learning and teamwork experiences as well as outcomes in a 5-day online transdisciplinary course. Application Design: 31 graduate students of engineering, industrial design, and health fields from 4 countries participated in online mixed-discipline instructional sessions and teams to
address a real industry challenge. A mixed-methods approach was used to examine students’ experiences and learning outcomes based on a competence measure, session participation data, student journal entries, team progress reports, team elaboration visuals, and final team presentations. Findings: Students’ knowledge of industrial design, medical considerations, ethics and standards, effective teamwork, and self-regulated learning were increased. Students’ high motivation helped them deal with the challenges involved. Daily student journals, team reports, and visual elaboration tools were found to be beneficial for determining the challenges and learning quality. The observed student progress within 5 days is promising, making it worthwhile to further explore the benefits of short online courses for increasing graduates’ readiness and establishing university-industry collaborations in education.Erasmusensuremath+ Programme of the European Unio
Modüler inşaat projelerinde risk yönetimi için çok kriterli karar verme yaklaşımı
No full textWhile there exists an ever-rising interest in modular construction projects, the current performance does not depict its full capabilities. This is mainly due to practicing 'stick-built' methods under a roof, implying carrying out conventional construction style in an offsite factory. That malpractice causes costs overruns, disruptions in timeline, and poor-quality end-products. Hence, early planning, guides, and qualified individuals should be integrated to eliminate those hindrances. While being minimal but not inexistent, the risks in a modular project can negatively impact overall performance if not tackled early on. As such, this study aims to utilize a multi-criteria decision-making approach for identifying the most efficient risk management approaches to tackle risks in modular construction projects. Hence, a systematic literature review, meta-analysis, semi-structured interviews with 5 experts, open- ended questionnaires with 5 experts who opted for sharing their input in this manner instead of interviews, and the 2- round Delphi method with 11 experts, were conducted. The data achieved underwent reliability, validity, and agreement tests comprising of calculations such as percentage standard deviation decrease, Cronbach's alpha, and Kendall's coefficient of concordance (Kendall's W). This was followed by a meta-analysis with the content derived from the literature review. Hereafter, the Analytical Hierarchy Process (AHP) was opted to quantify the Delphi findings and solve the multi-criteria decision-making process. This has led to ranking the risk management approaches according to efficiency for each risk category considered in the scope of this study. These risk categories are Supply chain, Health & Safety of workers, Stakeholders, and Governmental support. The Delphi scores pertaining to efficiency performance of each risk management approach according to the relevant risk criteria was incorporated in the spreadsheet where AHP scores were calculated. The AHP rankings are relevant to the mean efficiency score from Delphi round 2 and a uniformized weight value for risk criteria as a general approach. Practitioners can implement the spreadsheet with modified weight of the risk criteria according to their projects to derive precisely ranked risk management approaches. Furthermore, an interactive web-based application was launched using data achieved throughout the study to provide target audience with a user-friendly platform supporting early decision making in risk management. Once users select the risk category and criteria to tackle based on their projects, the application leads to guides on implementation of the risk management approaches alongside a to-do list. The application was validated by 3 industry experts for feasibility in integration to projects. The findings of this study will support early planning in a modular project by indicating to project managers or risk managers the most appropriate risk management approach to be implemented according to risk criteria of the project. The highly reliable Delphi and AHP findings provide practical insight for target audience in the modular construction industry such that a clearer initiation phase can be achieved. This would hence enable achievement of timelines, budget conditions and quality standards. The flexibility of the developed decision-making platform ensures that different projects can benefit from the latter based on their properties. Moreover, the research promotes continuous improvement in the modular construction industry by contributing to the quest of enhancing productivity through efficient risk management approaches usage.Modüler inşaat projelerine sürekli artan bir ilgi olsa da, mevcut performans tam yeteneklerini göstermiyor. Bu, esas olarak, bir çatı altında 'birleştirme' yöntemlerinin uygulanmasından kaynaklanmaktadır ve bu da, tesis dışındaki bir fabrikada geleneksel inşaat tarzının gerçekleştirilmesi anlamına gelmektedir. Bu yanlış uygulama, maliyet artışlarına, zaman çizelgesinde aksamalara ve düşük kaliteli nihai ürünlere sebep olur. Bu nedenle, bu engelleri ortadan kaldırmak için erken planlama, rehberler ve kalifiye bireyler entegre edilmelidir. Modüler bir projedeki riskler minimal olmakla birlikte varolmasa da, erken ele alınmazsa genel performansı olumsuz etkileyebilir. Bu nedenle, bu çalışma modüler inşaat projelerinde riskleri ele almak için en verimli risk yönetimi tekniklerini belirlemek doğrultusunda çok kriterli bir karar verme yaklaşımı kullanmayı amaçlamaktadır. Bu amaçla sistematik bir literatür taraması, meta-analiz, 5 uzmanla yarı yapılandırılmış görüşmeler, görüşme yerine girdilerini bu şekilde paylaşmayı tercih eden 5 uzmanla açık uçlu anketler ve 11 uzmanla 2 turlu Delphi yöntemi kullanılmıştır. Elde edilen veriler, yüzde standart sapma azalması, Cronbach's alpha ve Kendall's uyum katsayısı (Kendall's W) gibi hesaplamalardan oluşan güvenilirlik, geçerlilik ve uyum testlerinden geçirildi. Bunu, literatür taramasından elde edilen içerikle bir meta-analiz izledi. Bundan sonra, Delphi bulgularını ölçmek ve çok kriterli karar verme sürecini çözmek için Analitik Hiyerarşi Süreci (AHP) tercih edildi. Bu durum, bu çalışma kapsamında ele alınan her bir risk kategorisi için risk yönetimi yaklaşımlarının verimliliğe göre sıralanmasını sağlamıştır. Bu risk kategorileri Tedarik zinciri, İşçi Sağlığı ve Güvenliği, Paydaşlar ve Devlet desteğidir. Her bir risk yönetimi yaklaşımının ilgili risk kriterlerine göre verimlilik performansına ilişkin Delphi puanları, AHP puanlarının hesaplandığı elektronik tabloya dahil edilmiştir. AHP sıralamaları, Delphi 2. turdaki ortalama verimlilik puanı ve genel bir yaklaşım olarak risk kriterleri için tek tipleştirilmiş ağırlık değeri ile ilgilidir. Uygulayıcılar, kesin olarak sıralanmış risk yönetimi yaklaşımları elde etmek için projelerine göre risk kriterlerinin değiştirilmiş ağırlığı ile elektronik tabloyu uygulayabilirler. Ayrıca, risk yönetiminde erken karar vermeyi destekleyen, hedef kitleye yönelik kullanıcı dostu bir platform sunmak için çalışma boyunca elde edilen veriler kullanılarak etkileşimli web tabanlı bir uygulama hayata geçirilmiştir. Kullanıcılar projelerine göre ele alınacak risk kategorisini ve kriterleri seçtikten sonra, uygulama bir yapılacaklar listesi ile birlikte risk yönetimi yaklaşımlarının uygulanmasına ilişkin kılavuzları sağlar. Uygulama, projelere entegrasyonda fizibilite için 3 sektör uzmanı tarafından doğrulandı. Bu çalışmanın bulguları, proje yöneticilerine veya risk yöneticilerine projenin risk kriterlerine göre uygulanacak en uygun risk yönetimi yaklaşımını göstererek modüler bir projede erken planlamayı destekleyecektir. Son derece güvenilir Delphi ve AHP bulguları, modüler inşaat sektöründeki hedef kitle için daha net bir başlangıç aşamasının elde edilebilmesi için pratik bilgiler sağlar. Bu, zaman çizelgelerine, bütçe koşullarına ve kalite standartlarına ulaşılmasını sağlayacaktır. Ayrıca araştırma, verimli risk yönetimi yaklaşımlarının kullanımı yoluyla verimliliği artırma arayışına katkıda bulunarak modüler inşaat sektöründe sürekli iyileştirmeyi desteklemektedir
Can nacar, labor and power in the late Ottoman Empire: Tobacco workers, managers, and the state, 1872-1912
No full textN/
Measurement of the cross section of top quark-antiquark pair production in association with a W boson in proton-proton collisions at √s = 13 TeV
No full textThe production of a top quark-antiquark pair in association with a W boson (t (t) over barW) is measured in proton-proton collisions at a center-of-mass energy of 13TeV. The analyzed data was recorded by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb(-1). Events with two or three leptons (electrons and muons) and additional jets are selected. In events with two leptons, a multiclass neural network is used to distinguish between the signal and background processes. Events with three leptons are categorized based on the number of jets and of jets originating from b quark hadronization, and the lepton charges. The inclusive t (t) over barW(+) production cross section in the full phase space is measured to be 868 +/- 40(stat)+/- 51(syst) fb. The t (t) over barW(+) and t (t) over barW(-) cross sections are also measured as 553 +/- 30(stat)+/- 30(syst) and 343 +/- 26(stat)+/- 25(syst) fb, respectively, and the corresponding ratio of the two cross sections is found to be 1.61 +/- 0.15(stat)(-0.05)(+0.07)(syst). The measured cross sections are larger than but consistent with the standard model predictions within two standard deviations, and represent the most precise measurement of these cross sections to date.BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES and BNSF (Bulgaria); CERN; CAS, MoST, and NSFC (China); MINCIENCIAS (Colombia); MSES and CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); MoER, ERC PUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRI (Greece); NK-FIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MES and NSC (Poland); FCT (Portugal); MESTD (Serbia); MCIN/AEI and PCTI (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); MHESI and NSTDA (Thailand); TUBITAK and TENMAK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (U.S.A.).
Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 724704, 752730, 758316, 765710, 824093, 884104, and COST Action CA16108 (European Union); the Leventis Foundation; the Alfred P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S.-FNRS and FWO (Belgium) under the "Excellence of Science - EOS" - be.h project n. 30820817; the Beijing Municipal Science & Technology Commission, No. Z191100007219010; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Hellenic Foundation for Research and Innovation (HFRI), Project Number 2288 (Greece); the Deutsche Forschungsgemeinschaft (DFG), under Germany's Excellence Strategy - EXC 2121 "Quantum Universe" - 390833306, and under project number 400140256 - GRK2497; the Hungarian Academy of Sciences, the New National Excellence Program - uNKP, the NKFIH research grants K 124845, K 124850, K 128713, K 128786, K 129058, K 131991, K 133046, K 138136, K 143460, K 143477, 2020-2.2.1-ED-2021-00181, and TKP2021-NKTA-64 (Hungary); the Council of Science and Industrial Research, India; the Latvian Council of Science; the Ministry of Education and Science, project no. 2022/WK/14, and the National Science Center, contracts Opus 2021/41/B/ST2/01369 and 2021/43/B/ST2/01552 (Poland); the FundacAo para a Ciencia e a Tecnologia, grant CEECIND/01334/2018 (Portugal); the National Priorities Research Program by Qatar National Research Fund; MCIN/AEI/10.13039/501100011033, ERDF "a way of making Europe", and the Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de Maeztu, grant MDM-2017-0765 and Programa Severo Ochoa del Principado de Asturias (Spain); the Chulalongkorn Academic into Its 2nd Century Project Advancement Project, and the National Science, Research and Innovation Fund via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation, grant B05F650021 (Thailand); the Kavli Foundation; the Nvidia Corporation; the SuperMicro Corporation; the Welch Foundation, contract C-1845; and the Weston Havens Foundation (U.S.A.).Publisher versio